Spinal fusion is a surgical technique used to join two or more vertebrae for the correction of various conditions, such as back pain caused by degenerative conditions, misalignment, scoliosis, injury causing misalignment, or abnormal intervertebral motion. Spinal fusion may be indicated for the cervical region or, (more rarely,) the thoracic or lumbar regions.
Spinal fusion, and particularly intervertebral (or interbody) fusion, is accomplished by immobilizing vertebrae relative to one another with one or more surgical implants, removing a portion of material between the vertebrae, and providing graft material between the vertebrae. The material removed typically includes the intervertebral disk, but may often include part(s) of one or both of the adjacent vertebrae. Graft material typically includes supplementary bone material, which may be obtained from the recipient, from a donor, a synthetic substitute, or any suitable combination of the above.
Successful fusion requires that the relative orientation of the fused vertebrae be maintained, as well as the spacing between them. Although the vertebrae may be fixed by mechanical implants, such as rods, plates, or cages connected to the vertebrae by screws, or by exterior support in the form of orthotic bracing, these approaches provide only a limited degree of compressive support to the spine.